Generally this type of liquid fuel burning apparatus is provided with a lowering device for detecting vibrations such as earthquakes during combustion and automatically lowers the combustion wick to extinguish the fire. This type of apparatus is designed so that when the wick is manually lowered, the lowering stroke is shortened to eliminate the bad odor given off during fire extinguishment. This is shown in FIGS. 1 through 4. In these figures, the numeral 1 denotes an oil tank having a burner section 2 on its top.
The numeral 3 denotes a wick vertically slidably installed in the burner section 2 and constantly urged in the lowering direction by a spring (not shown).
The numeral 4 denotes a wick shaft rotatably mounted on the apparatus, having attached thereto at one end a pinion 5' meshing with a rack 5 fixed to the wick 3 and at the other end a knob 6 for the wick shaft 4, the arrangement being such that the rotation of the knob vertically moves the wick 3.
The numeral 7 denotes a support fixed to the wick shaft 4 by a screw 8, and 9 denotes a rotary plate fixed to the support 7 and having a pin 10 fixed to the upper portion thereof.
The numeral 11 denotes a ratchet wheel rotatably mounted on the support 7 and formed around its outer periphery with a projection 11a and a plurality of teeth 11b, said ratchet wheel 11 having a throughgoing slot 11c in which said pin 10 slides.
The numeral 12 denotes friction members fixed to the opposite surfaces of the ratchet wheel 11 and urged by friction members 13 in the form of spring sheets.
The spring members 13 are held in position on the support 7 by restraint members 14.
The numeral 15 denotes a vibration sensing device attached to the top of the oil tank 1 and comprising a weight 16 and a lever 17 operable by said weight 16, said lever 17 being formed at its front end with a locking device 18 for the wick 3.
The locking device 18 comprises the lever 17, an auxiliary lever 19 mounted on the front end of said lever 17, and a spring 20 for urging said auxiliary lever 19 to the ratchet wheel 11.
The front end of said auxiliary lever 19 is formed with a locking portion 19a adapted to mesh with the teeth 11b formed on the ratchet wheel 11, the engagement between said locking portion 19a and the teeth 11b preventing reverse rotation (counterclockwise rotation, in the figure) of the ratchet wheel 11.
Further, the front end of said lever 17 is formed with a stop 17a adapted to abut against the projection 11a on the ratchet wheel 11 to stop rotation of the ratchet wheel 11. In addition, the optimum burning position for kerosene fuel sucked up by the wick 3 is so designed that it corresponds to the height (point a in FIG. 4) of the wick 3 obtained when, as shown in FIG. 2, the stop 17a on the lever 17 abuts against the projection 11a on the ratchet wheel 11 and the pin 10 fixed to the rotary plate 9 abuts against the terminal end of the throughgoing slot 11c formed in the ratchet wheel 11.
Further, the lever 17 and auxiliary lever 19 of said locking device 18 are adapted to move in the direction of arrow A in FIG. 2 when the vibration sensing device 15 is actuated, thereby canceling the locking between the ratchet wheel 11 and the locking device 18.
The numeral 21 denotes an emergency fire extinguishing device so designed that a knob 21a is rotated separately from the vibration sensing device 15 to move the lever 17 which is connected to the knob 21a with a chain, etc., in the direction of arrow A in FIG. 2, thereby canceling the locking between the locking device 18 and the ratchet wheel 11.
In addition, 22 denotes an inner wick cylinder and 23 an outer wick cylinder.
In such apparatus, when it is desired to decrease the height of the wick 3, the knob 6 is rotated counterclockwise. Then, although the ratchet wheel 11 is locked by the locking device 18 and cannot be rotated, the knob 6 is rotated by overcoming the frictional force of the friction members 12 and 13 and lowers the wick 3. Further, in the normal fire extinguishment, the knob 6 is rotated counterclockwise until the pin 10 fixed to the rotary plate 9 abuts against the other terminal end of the throughgoing hole 11c formed in the ratchet wheel 11, as shown in broken lines in FIG. 2 (the angle of rotation of the knob being about 300.degree. in the figure), thus lowering the wick 3 to point b in FIG. 4.
If a vibration such as caused by an earthquake is applied to this kerosene burning apparatus, the weight 16 of the vibration sensing device 15 senses this situation and moves the lever 17 in the direction of arrow A in FIG. 2. Then, since the ratchet wheel 11 is released from the locking device 18, the urging force of the loaded spring (not shown), which has a downward force, quickly lowers the wick 3, thus instantly extinguishing the fire on the wick 3. Further, when it is necessary to extinguish this kerosene fuel burning apparatus in an emergency for a reason other than a vibration such as caused by an earthquake, the knob 21a is rotated to move the lever 17 in the direction of arrow A in FIG. 2, whereby the fire can be instantly extinguished in the same manner as described above. In the case of the emergency fire extinguishment described above, the ratchet wheel 11 is released from the locking device 18. When the ratchet wheel 11 is released from the restricted position imposed by the locking device 18, the wick 3 which has been indirectly restricted in position by the ratchet wheel 11 is released from the positional control imposed by the ratchet wheel. Therefore, the wick 3 is rapidly lowered to point c in FIG. 4 by the spring (not shown) which has stored force in the lowering direction.
In addition, the positions of the wick 3 for normal fire extinguishment and for emergency fire extinguishment differ from each other, as indicated at points b and c. The reason for this difference is as follows: In the case of normal fire extinguishment, since the rotation of the pin 10 on the rotary plate 9 is restricted by the throughgoing hole 11c of the ratchet wheel 11, the wick 3, whose upper and lower positions are associated with the rotation of the rotary plate 9, is naturally restricted in position by the terminal end of the throughgoing hole 11c; on the other hand, in the case of emergency fire extinguishment, the ratchet wheel 11 is also rotated along with the wick shaft 4 and the lowered position of the wick 3 is not restricted by the throughgoing hole 11 of the ratchet wheel 11 and, therefore, the wick will go down to the point c, the lowermost position.
However, such apparatus is cumbersome since the knob 6 must be rotated manually during normal fire extinguishment.
On the other hand, there is an arrangement intended to avoid such cumbersomeness and adapted to be operatively connected to the vibration sensing device even when normal fire extinguishment is to be effected so that the fire can be put out instantly. In such apparatus, however, since the fire is put out in as short a time in normal fire extinguishment as in an emergency, the liquid fuel vapor being produced in the high temperature wick guide cylinder flows into the combustion cylinder which is still hot, where the vapor is thermally decomposed to produce aldehyde or the like whose smell makes the user feel unpleasant.